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Md-11 maintenance technician reported 3 incidents of nose wheel bearing failures.
| Attributes | |
| ACN | 1480029 |
| Time | |
| Date | 201708 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Flight Plan | None |
| Component | |
| Aircraft Component | Nose Gear Wheel |
| Person 1 | |
| Function | Technician |
| Qualification | Maintenance Airframe Maintenance Powerplant |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy |
Narrative:
General safety concern to raise awareness of recent safety of flight issue. Three incidents of nose wheel bearing failure on company md-11 aircraft have occurred within the last 10 months [on three separate aircraft at 3 separate locations]. Through our software I do not see this happening prior to 11/xx/16. This issue happens at high speed during takeoff and landing. Douglas md-11 nosewheel installation and design is unique to all other company fleet types. My observations are as follows:1) md-11 nose wheel final torque is the lowest of all company fleet 25ft/lbs. Initial torque is also comparatively low. 2) axle sleeve that contains both inner and outer bearing races (possibly migrates).3) tang washer part# ACG7220-1 contains a small 90 degree lip. This lip must fully seat in narrow channel made by axle and axle sleeve. 4) tang washer is a snug fit circumferentially (possibly cocks sideways during installation). 5) safety bolt does not go through axle. Douglas md-11 nose gear design is cantered and set back further. During hard turns heavy side loads occur on the wheel and axle in the direction of the turn.
Original NASA ASRS Text
Title: MD-11 Maintenance Technician reported 3 incidents of nose wheel bearing failures.
Narrative: General safety concern to raise awareness of recent safety of flight issue. Three incidents of nose wheel bearing failure on Company MD-11 aircraft have occurred within the last 10 months [on three separate aircraft at 3 separate locations]. Through our software I do not see this happening prior to 11/XX/16. This issue happens at high speed during takeoff and landing. Douglas MD-11 nosewheel installation and design is unique to all other Company fleet types. My observations are as follows:1) MD-11 nose wheel final torque is the lowest of all Company fleet 25ft/lbs. Initial torque is also comparatively low. 2) Axle sleeve that contains both inner and outer bearing races (possibly migrates).3) Tang washer part# ACG7220-1 contains a small 90 degree lip. This lip must fully seat in narrow channel made by axle and axle sleeve. 4) Tang washer is a snug fit circumferentially (possibly cocks sideways during installation). 5) Safety bolt does not go through axle. Douglas MD-11 nose gear design is cantered and set back further. During hard turns heavy side loads occur on the wheel and axle in the direction of the turn.
Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.